The present invention concerns a portable device including a case in which there is arranged a first electric module, and a wristband or bracelet attached to the case, the case including a top portion and a bottom portion which cooperate with each other in order to assemble the case, a second electric module being associated with the wristband and electric connecting means providing an electrical connection between the first and second electric modules through an aperture arranged in the case, the first electric module including at least one electric bump contact capable of being connected to the electric connection means.
More particularly, the present invention concerns a portable device of this type including means for establishing contact between the electrical connection means and the first electric module, inside the case, in a removable manner.
In the present description, “electrical connection means” means any conductor or set of conductors enabling an electrical connection to be made between two electric modules. Likewise, “electric module” means any device for providing or receiving an electric supply and, if necessary, transmitting or receiving an electric signal.
In a preferred embodiment, the portable electronic device is made in the form of a portable electronic instrument taking the shape of a wristwatch including means for receiving and possibly transmitting radio frequency type signals. In such case, the first electric module includes electronic processing circuits for the electric signals exchanged with the second electric module, the latter including an antenna.
Such portable devices have already been disclosed in the prior art proposing various solutions concerning the means for securing the electric connecting means to the first electric module.
European Patent No. 0 631 341 discloses an electronic instrument of the wristwatch type including an antenna housed in the wristband and connected to electronic circuits for processing the signals received by the antenna. The electronic processing circuits are arranged inside the case of the instrument on a printed circuit board. Bump contacts are arranged on a peripheral region of the printed circuit board for establishing an electrical connection between the connection terminals of the antenna and the electronic processing circuits. The solution disclosed in this document for providing the electric connection between the antenna terminals and the bump contacts of the printed circuit board consists in using fixing screws passing through suitable openings, arranged in the antenna terminals, and screwed into the printed circuit board in the vicinity of the bump contacts.
This solution has, however, certain drawbacks, particularly when the electronic instrument is assembled, in that it is necessary to provide holes in the printed circuit board for receiving the screws and in that a screwing step is indispensable. Moreover, any subsequent replacement of the antenna in the event of a problem means that the instrument case has to be completely dismantled, before the fixing screws can be accessed, which can make this operation awkward.
A different solution for providing the connection between the antenna terminals and the electronic processing circuits is set out in the same Patent in the presentation of the prior art. This alternative is based on the use of a leaf spring type connector, for each antenna terminal, onto which an electrical conductor, connected to one of the antenna terminals, is pressed.
Such an embodiment makes assembling the wristband and the antenna easier than in the solution previously described, in that the electrical conductor need only be plugged into an opening in the case in order to establish the electric contact.
However, this solution also has drawbacks, in particular from the point of view of its durability over time. Indeed, the leaf spring is typically welded onto the printed circuit board, which has to be carried out with care to guarantee sufficient mechanical resistance with respect to the perpendicular stress exerted on the spring, once the electrical conductor is placed pressing against it. It should also be noted that the contact surfaces between the spring and the electrical conductor are not protected, which can lead to stability problems for the electrical connection, due particularly to possible oxidation of the free metal surfaces. Moreover, this solution is relatively bulky and consequently cannot be suitable for making an instrument of small volume.